Not Applicable
1. Field of the Invention
The present invention relates generally to rollers for roller conveyors and more specifically to a conveyor roller with a telescoping shaft having tapered ends.
2. Description of Related Art
A conveyor roller generally is rotatably mounted on a shaft, which, in turn, is mounted in openings located in laterally spaced side frame members of the conveyor.
The shaft is generally loosely positioned in the mounting aperture and vibration and loading conditions of the roller causes the shaft to bounce, causing noise and wear on both the shaft and the aperture. Over time, the wear from shaft vibration results in enlargement of the mounting aperture, creating an even looser fit between the shaft and the frame and generating even more noise. Eventually, the shaft vibration causes the frame to cut through the roller shaft, resulting in the roller dropping out of the frame.
It would accordingly be desirable to modify the mounting of a roller shaft in a conveyor frame to minimize the vibration of the shaft in the frame and thereby lessen the noise which is produced and the wear which occurs on both the shaft and the frame.
It also is desirable to be able to replace rollers easily when they become worn. It further is desirable to be able to assemble the roller axles by hand immediately prior to being placed into the roller assembly. This eliminates the use of tools required for crimping, drilling, pinning, or staking of the axle.
According to this invention, the mounting of a conveyor roller to the conveyor frame members is improved by the use of a roller shaft which is telescoping and has tapered ends. The roller shaft preferably is of two-piece telescoping tubular construction with a spring positioned inside the telescoping tubular members urging the members away from each other. The tubular construction of the shaft or axle provides added strength in the middle of the span compared to a solid hex axle and keeps the axle aligned with the bearings without being distorted out of alignment when subjected to a load.
The ends of the shaft are tapered outwardly and engage the mounting holes in the conveyor frame to eliminate play between the shaft and the mounting holes. The tapered ends allow replacement rollers to be placed into mounting holes that have been enlarged by wear and still seat firmly.
The tapered ends of the shaft and the mounting holes are shaped to prevent rotation of the shaft. Preferably they are both hexagonally shaped, but can be square or round with one or more flats.
Other objects and advantages of the present invention will become apparent from the following description and the accompanying drawings which are merely illustrative of the invention.